Grain damage (%)(a), Grain weight loss (%)(b) and Feeding Deterrence Index (%)(c) (Mean ± SE, n = 3) due to Tribolium castaneum exposed to various crude plant extracts (Zingiber officinale, Syzygium aromaticum, Nicotiana tabacum and Azadirachta indica) at different exposure intervals. Plant extracts are on x-axis and measured variables are on y-axis. DEI = Days exposure interval; Means with different letters are significantly different (P < 0.05), Bonferroni test, comparisons across all treatments.